/Engine/Source/Runtime/Engine/Classes/Engine/Engine.h
void SwapPlatformUserId ( [ULocalPlayer](API\Runtime\Engine\Engine\ULocalPlayer) * NewPlayer, const [FPlatformUserId](API\Runtime\Core\Misc\FPlatformUserId) CurrentUserId, const [FPlatformUserId](API\Runtime\Core\Misc\FPlatformUserId) NewUserID ) const